The only non-local terms in \({m_{global,k}}\)  are the full dataset statistics \(\mathcal {S} = \lbrace \Pr (Y=1,A=0), \Pr (Y=1,A=1)\rbrace \) .
These statistics \(\mathcal {S}\)  can be aggregated at the server using a single round of a secure aggregation scheme (e.g., [1]}) at the start of training and then shared with the \(K\)  participating clients to enable them to compute their global fairness component \({m_{global,k}}\) .
